Computational Investigation on Aerodynamic Characteristics of Low-Aspect-Ratio NACA 4412 Wings in Low-Re Flows: Comparative Study on CFD and Panel Methods

This study presents a comprehensive evaluation and comparison on the performances of the vortex lattice method (VLM), the 3D-panel method (PM), and the computational fluid dynamics (CFD) methods for the Reynolds-averaged Navier–Stokes (RANS) equations and large-eddy simulation (LES) in predicting aerodynamic characteristics of low-aspect-ratio wings in low-Reynolds number flows. The primary aim is to investigate the capability of the models in capturing separation bubbles and complex flow behaviors with a particular focus on a wide range of high angles of attack. Accordingly, the low-aspect-ratio (AR = 1 and AR = 3) wings with a well-known NACA 4412 airfoil have been modelled and investigated at the Reynolds numbers 2.5 × 104 and 7.5 × 104 using the aforementioned methods to make a comparison on lift and drag prediction capabilities. The grid independence studies are conducted for both methods and ensure that the results are independent of the number of mesh or panel elements. Initially, the results of VLM and PM are compared with the RANS CFD analysis results carried out using k–kL–ω transition turbulence model. The further analyses are performed using various turbulence models (RNG k–ε, transition SST, k–kL–ω transition, realizable k–ε models), and the results are compared with large-eddy simulation (LES) analyses and the experimental wind tunnel data available in literature.